Oil-well underreamer



' June '29 1926.

W. H. S. MOORE OIL WELL UNDERREAMER Filed May 51.1922

2 Sheets-Sheetl 2 Patented June 29, lge.

MENTE@ WILLIAM H. S.,1V{OORE,

OF CLEVELAND, OHIO.

OIL-WELL UNDERBEAMER.

Application filed May 3l,

lviy invention relates in general to tools for drilling wells, such as oil, gas, and artcsian, and more particularly to underreamers. In drilling wells,V the cutting tools must pass through the pipe 'forming the well casing, and with the solid bits in general use the hole can ynot be made larger than the inside diameter of the casing. ln order that the casing may be easily driven downwardly, the hole must be enlarged in ladvance of the casing` to a size somewhat larger than the outside diameter of the usual driving shoe on the end of the casing, and the couplings connecting 'the sections oi cas ing. This is accomplished by a tool known as an underreamer'. The cutters or bits of this tool must be so mounted that the underreamer may pass freely downwardly or upwardly through the casing, and when below the end or" the casing will expand auton'iatically so that in working they will enlarge the hole to a diameter of therequisite size relatively to that of the casing.

rin object oi the invention is to provide an underreamer in which the cutters or bits are securely housed, can not become detached, or tall into the hole it brokem and in which the bits can not snag or bind in the casing while being inserted or withdrawn.

The manner of connecting cutters to the body of the reamer has heretofore been a weak point in such tools. In most of the tools heretofore used the cutters have been on a saddle which slides up and down in the body and held in position by a spring which .fairies the entire weight ot the cutters. i The connection between the cutters and the saddle has been a point ot weakness and cutters 'trequently break at this point, letting about 90% of the cutters drop in the hole. cutters are exceedingly diliicult to iish out oi" the hole` and holes have often been abandoned 'tor the reason that it was impossible to [ish ont the cutter.

lt' is an object of the present invention to provide a. tool in which the cutters have greater strength and durability tor the reason that the bits in operating` position are in solid contact with substantial portions ot the body and receive the impact in such manner that they are capable of withstanding great shocks and strains incident to the blows delivered in drilling.

A further object of the invention is to prolvide improved means tor expanding and col- Such 1922. Serial No. 564,791.

lapsing the cutters, which positively prevents the cutters from becoming cocked, i. c., one set while the other is wholly or partly collapsed, either in working position or during insertion or withdrawal of the tool. Y

A :further object is to provide an expanding and collapsing means for the cutters which insures positive setting of both cutting' bits automatically when the tool comes to working position beneath the end of the casing, and in which the tools are rigidly held in extended position while operating.

il further object is to provide a tool in 'which the cutters are free to move to a position entirely within the body while in the well casing during the insertion or withdrawal ot the tool.

ln reainers heretofore used much trouble has been caused by the failure ot the cutter collapsing mechanism to operate properly when the tool is withdrawn from operative position into the casing. This is caused by the driving shoe at the lower end of the casing (getting out of round, and as this is depended upon to collapse the cutters as the reamer is withdrawn, only one cutter will engage the shoe and be drawn down to the collapsing point, while the other cutter remains in expanded position or nearly so, and wedges in the casing. In such cases the entire casing has to be pulled7 in order to remove the tool.

lt is an object of the present invention to overcome the above mentioned difficulty by providing a plurality ot trips separate from the cutters for controlling the critter lockingand releasing means, the trips being operable upon being raised into engagement with the casing` to release the cuttersfactuation oi' one oit the trips being suiiicient to release all the cutters so that in the event the driving slice gets out orn round there is no danger oi failure ot the cutter collapsing devices.

A 'further object ot the invention is to provioe a cutter controllingmechanism which will enable the tool to be withdrawn from the casing and cutters removed therefrom and replaced without the necessity tor resetting the tool beiore it is reinem-ted in the casing.

A iurther object is to provide a tool in which the cutter Setting spring operates upon a locking vdevice separate from the cutloads in use. Vylliis enables the Cutters to be keasily set inoperative position or collapsed.

A further object is to provide a tool which has positiveV guiding means which prefaients it from Working out ofalignment with the casing.

Other objects will be apparent from` the followingdescri ption .and the annexed drawings. f Y

The ollmving'descriptidn andV accompanju ingzdraw-ings set ltorth indetail certain means einbodyingI my invention, thc disclosed means, however, constituting but one ofA the various mechanical 'forms in which the principle of the. invention may be appli-ed.

, inse-.id annexed drawings, Fig. l; is alom Vgituglinal yaxial sectionl teken through the cut-ter releasing; trips, Fig. 2 is a lonoitudinal: axial section .takenl at right angles .to the section, shown` in Fig.` 1, and showing the cutters in expanded position.. 3 is a sectionsimiler to Fig. 2 showing the cutters in collapsed position; Fig. dA is a fragmentary section similar'to Fig. 1 showm ing the trips in retracted position. Fig.

is a perSpeCtiye-fview of `a cutter;l Fig. y6 is a side elevation. o, lthe tool lookingI vto- Ward one of the cutters; Eig. 7 is a side elevation of the tool looking toward-` one of the trips,k a portion being broken vaway to show part of the trip mechanism; Fig. 8

is a section on line 8-8 of, Fig. 1;, Figi. 9 is -a section ont line` 9--9l o- Fig. l; Fig. 10 is avsectionj on line, 10ml() of Fig.. 2P.

Referring to the annexedichrawings, the tool has a: ymain. bodyV `portion 1 in which the cutters and cutteractuating mechanism are mounted.. 'llhe body portion 1 ifs circular in cross section, and has a steppedv upper end consisting, ot a; reduced threaded portion 2 andstill further Ireduced extension 3 above the threaded portion 2, and a threaded. nipple d at the end of the reduced portionY 3. At its lower end the body meinberl lia-sla threadednipple 5 to which `may be attached either ay pilot .member or a tool holder; I'.

connecting member Gis attached to the upperend. of the body member l, said member havingl a threaded socket 7, whereby itean he screwed .upon the end nipple 4 et the body member. The connecting member Gllias a threaded nipple 8 at; its; upper end, by means of which it may be ,connectedV to the actuating; rod. Theconnecting memberv 6 has an.v axialbore 9 extend-ing` fromfits upper end tov a. counter bore 10`- at the lower end thereof. The body member 1 vhas an axial bore 11 of the same diameterat the counter bore l()vv infthe connecting; member 6; Y

Adjacent its lower end the body-.member 1 has a slot 12 diametrically therethrough to receive the cutters.` At'the upper ond of the slotl2 upwardly-extending channels 13 are provided on opposite sides ci" the body to receive the Shanks of the cutting tools. Each of the channels 13 has a recess 'le' in the bottom thereof at its upper end.

than the head and fitting in the grooves 13 of the body. Theshanlr l16 of each of the tools has an `inner projection 17 at its upper end adapted to lit in the recess 1,114 atl the upper outer upper edge The heads of the cut-V ters 15. 'twithinxthe slot 12in thebody l and have pivotal movement about their upper` ends. whereby the-heads of the Vcutters may .bei swung out. to pro-ject the required The Y cutters each have a shanlr 15 narrower j endV of the groove 13, and a :rabbet 18 at its Y distance fronithe outer Ylace of the tool. in

the slot 12 beneath the cutters` 15 is mounted a. followerlQ which is slidably VLoimted `upon an axial pin 2Oy rrigidly secured 21 .fixed `Within the bore 11 adjacent the lower end of the bod i member The tollo-Wer 19 hasa ,tubular boss 22 slidably litting` Within the bere 11 and end flanges 2 3 Ywhich. arellush with the-.outer surface of the body member 1. A light coil spring 2.4L Within the boss 22 and interposed betueen the plug 21 and the follower 19 serves to normally hold the follower 19'l in engagement With the under faces of the cutters 15. U follower 19 hasl an upper face 25 which has a slight incline downwardly from the center to the ends thereof so that the follower is readily forced down when the cutters 15 are moved to collapsed position. The V'tolloWer 19 alsoV serves to .prevent the cutters from falling 'into the hole Ashould the cutter be broken or torn looseliroin the body member,4 and also to prevent entranceV of rock, splinters, mud, or other `fore-ign matter Within the body. i y

.it the upper end or"v the cutter receivlig slot 12 the body 1 is .provided'withy a central rectangular recess 26 in which "isv slidably Y to i a plug i The Y l Ui) los l'lO

mounted a Wedge Vblock 27 which serves to torce the cutters 15 outwardly into cutting position, and to rigidly hold the cutters. in such position. The lower end of the wedge block 27 is` pointed so that asthe blodl is Jforced downwardly the cutters 15 areA spread Vapart andi'orced into Wo-rlringposition. The body portionot the-*block 27, however, has parallel side Walls Vagainst which the' inner laces otthe cutters 15 abut i wheny in Working position so that impacts on the tool do not tendto; dislodge the block 27 and,` the cutters 15 are rigidly held in workingA position. f

Mounted Within the Wedge block 27 is a roller 28 which has a peripheral` groove adjscent each;- end. rldhebloclr 27- is provided with vertical apertures 29 leading tothe grooves at theends ol the-rollerl28 onopposite sides or" theroller. Y l

Adjacent its upper end the body mem ber 1 is provided with a rectangular slot extending diametrically therethrough, in which is mounted a pulley block 30. The pulley bloclr has a central bore 31 et' the same diameter as the bore 9 in the member 6. The bloclr 3() is provided with recesses 32 on opposite sides of the central bore 81, in each otf which are mounted a double sheave A cable 84 passes over the sheave 33 at one side et the center, extends downwardly through the axial bore 11 ot the body member, is threaded through the apertures Qi) and over one` end oi. the grooved. roller 2S, extends upwardly within the axial bore 11, and is passed over the sheave 33 at the saine side ot the center oi the block. A second cable 35 is passed over the sheave 33 on the opposite side and the roller 28 in the wedge block 27 in exactly the saine manner. rEhe ends of the cables 34 and 35 are connected to slides 3G which are mounted in diametrically opposed grooves 37 in the body member 1. A rod 38 is rigidly connected to the wedge block 27 at its lower end, extends upwardly through the sheave block SO, and has its upper end slidably fitting in the bore 9 oit the coimecting member G. rl`he rod 38 has a lined collar B9 which seat-s upon the top oit the sheave block 3() when the wedge block 2T is in its lowermost position. A coil spring 40 is interposed between the fixed collar 39 and the shoulder at the upper end ot the counter bore 10 inthe connecting member 6.

The spring 40 serves to normally hold the wedge block 27 in its lowerinost position in which position the cutters 15 are held in working position. n the grooves 37 of the body member 1 beneath the slides 36 therein are mounted slides 41 in the torni oit narrow elongated strips fitting in said groove. Each. slide 41. has an inturned upper flange which sets against the bottom oi the groove, a trip receiving slot 43 in its outer wall, an inwardly j )iojecting rib- 44 beneath the slot 43 corresponding in height to the tiange l2 and ei'igaging the bottom ot the groove 3T, and a downwardly projecting portion which lits in a shallower groove 45 forming continuation of the slide groove 37.

in each ot the slides 41 is pivotally mounted a trip member' 46 which depends troni its pivot, has a thickened lower portion 47. is provided with an upper engaging shoulder 4S, and has a rounded edge 49 at its lower end, Each pivoted trip member 45 has journalled. therein a roller 50 which travels upon the bottom ot' the groove 37,

and is adapted to env'ao'e in either ot two.

D W3 conca recesses 51., 51a.v in the bottom ot the longitudinal groove 37.

The slides 41 are connected to the slides 36 by means of short bolts 52 and are normally held apart by means oi coil springs 53 surrounding the bolts 52 and interposed between the slides 36 and 41.

When either one or both ot the slides 41 are moved downwardly the wedge block 27 is raised clear ot the cutters 15 and the cutters are free to swing inwardly within the slot 12 of the body member. Upward movement ot' the wedge block 27 compresses the coil spring 40 so that when the slides 41 are released the wedge block 27 is forced downwardly by the spring 40 into engagement between the inner faces ot the cutters 15 orc ing the cutters int-o working position.

The slides 41 are locked in their lowerniost position in which the wedge block 27 is held clear of the cutters by holding the pivoted trip members 46 in retracted position, with the rollers 5() engaging in the lower recesses 51, as shown at Fig. 4, while the tool is being inserted into or withdrawn from a well casing, the trips 46 being held in this p0sition by the wall of the casino".

rJhe upper portion of the body member 1 is enclosed by a sleeve 54. The lower end ot the sleeve 54 engages a shoulder 55 on the body 1, and also the external shoulder formed by the rabbet 18 on the outer side ot the upper end ol` the cutter shank 16.

v A threaded collar 56 is screwed onto the threaded portion 2 of the body member 1 and clamps the .sleeve 54 against the shoulder 55. The body member 1 within the sleeve 54 is turned to a slightly smaller diameterexcept adjacent the ends and center of the sleeve, leaving low peripheral ribs 57 'for bearing engagement with the sleeve 54.

In Fig. 2 of the drawing a well casing 58 provided with a driving shoe 59 at its lower end is shown. 1n Figs. 1 and 2 a pilot or guide member 60 is shown screwed upon the lower nipple 5 of the body member 1.

In Fig. 3 of the drawing a tool holder 61 is shown attached to the lower end ot the body member 1. The tool holder 61 may carry a drilling tool or a cleaning tool.

To lower the tool into a well, the .slides 41 are pulled down until the trip rollers 50 ene gage the lower recesses 51 and held in this position until the cutters 15 have entered the upper end ot the well casing. As the tool is lowered the trip members 46 are engaged by the wall ot' the casing and are held in their retracted position with the rollers 5() in the recess 51. The outer tace of the thickened portion 47 of the trip members 46 is of suliicient length so that the trip members 46 are prevented from springing out in passing the joints in the well casing. Should a joint be unusually wide the rounded lower corner 49 oit the trip will serve to return the trip to its inner position as the trip moves past the joint. As soon as the trip members 46 pass through the driving shoe 59 of the caslll) body member having upper and lower recesses into which said trip member is adapted to be retracted.

G. ln a drilling tool, a body member having a cutter receiving slot therein, a cutter mounted for lateral movement in the slot, a slide having a tapered lower end engageable with the cutter to move the cutter to working position, said slide having a flat portion 'lor holding the cutter in working position, and a spring pressed 'follower in said slot beneath the cutter and engaging the lower end of Jghe cutter in all positions thereof.

7. in a drilling tool, a body member having a cutter receiving slot therein, a pair oit pivotally suspended critters movable from a position entirely within the body member to working position in which the lower cutting edges project laterally from the body, a spring pressed slide movable downwardly into engagement with the cutters to shift the same to cutting position, means engageable with the well casing for retaining 'the slide in retracted position, and a spring pressed follower enga-geable with the lower ends ot' the cutters in all positions thereor.

8. In a drilling tool, a body men'iber having a transverse slot therethrough and longitudinal grooves on opposite sides thereol' extending upwardly from the top of the slot, a pair of cutters having enlarged heads litting in said slot and Shanks fitting in said grooves, said heads having shoulders at the sides of the shank and said slot being formed with shoulders against which the shoulders of the cutter bear, means for pivotally supporting the cutters adjacent the upper ends ot the slot, said shanlrs having squared upper ends engao'eable with the ends oi the slots when 'the cutters are in working position, a sleeve detachably secured to the body member and covering the upper ends of the slots to retain the cutters, and means tor moving the cutters to and from working position.

9. n a drilling tool, a body member having a transverse slot therethrough and longitudinal grooves on opposite sides thereof extending upwardly 'from the slot, said grooves having recesses in the bottoms thereor" at their upper ends, said recesses having` square shoulders at their lower sides, a pair ot cutters having heads lfitting within the slot and shanlrs fitting within the grooves, said shanlrs having` projections on their inner sides projecting into the recesses, said projections having square shoulders engageable with the shoulders at the lower sides ot the recesses, said shanlrs having a pivotal movement aboutthe interengaging shoulders of the recess and projection and said cutters having squared upper ends which abut against the upper ends o'iE the grooves when the cutters are in working position, a sleeve detachably secured to the body member and covering the upper ends of the grooves to re^ tain the cutters, and means for shifting the cutters to and from working position. n

in testimony whereof', I hereunto atx my signature.

VVILLlAM H. S. MGORE. 

